I was puzzled as well. There is an analogous of the FFT method of multiplying polynomials and integers to the matrix multiplication case [1], but it is not as s

I was puzzled as well. There is an analogous of the FFT method of multiplying polynomials and integers to the matrix multiplication case [1], but it is not as simple and probably does not belong in an introduction to linear algebra. [1] http://arxiv.org/abs/math/0307321v2 http://arxiv.org/abs/math/0307321v2